1.Field of the Invention
The present invention relates to the field of liquid crystal displays (LCDs), and more particularly, to a color filter (CF) substrate and a method of manufacturing the same. Further, the present invention relates to an LCD panel comprising the CF substrate.
2.Description of the Prior Art
An alignment mark plays an important role in the process of manufacturing an LCD panel. The way of ascertaining locations and calculating coordinates is to read the location of the alignment mark. For example, the location of the alignment mark has to be read when coordinates are located with sophisticated measurement equipment. The location of the alignment mark also has to be read when the alignment mark is exposed with an exposure machine. For assembling the LCD panel, it is necessary to use the alignment mark to ascertain an location of an active array substrate and a CF substrate.
Please refer to FIG. 1 illustrating a schematic, diagram of an lignment mark 1010 on the CF substrate in the conventional technology.
As shown in FIG. 1, a plurality of valid pixel domains 100 and an invalid pixel domain 101 surrounding the plurality of valid pixel domains 100 are disposed on a transparent substrate 10 of the CF substrate in the conventional technology. A black matrix pattern is formed on the invalid pixel domain 101 and used as the alignment mark 1010. The alignment mark 1010 could be a square or a cross in shape.
Please refer to FIG. 2 showing a partial cross-sectional view of the invalid pixel domain 101 as shown in FIG. 1. A transparent conducting layer 120 is disposed on the invalid pixel domain 101 disposed on the transparent substrate 10. The transparent conducting layer 120 is also disposed on the alignment mark 1010 and the peripheral domain of the alignment mark 1010 completely. That is to say, the alignment mark 1010 and the peripheral domain of the alignment mark 1010 covered by the transparent conducting layer 120 have the same feature of coverage.
The alignment mark 1010 could not be read by a CCD (charge-coupled device) optical reading lens because the alignment mark 1010 and the peripheral domain of the alignment mark 1010 have the same feature of coverage, that is, no optical differences. Accordingly, the success ratio of reading the alignment mark 1010 is low or even zero, resulting in a faulty location accuracy, a low equipment utilization rate, low manufacturing efficiency, and low production capacity.